LL-37

LL-37 is a synthetic 37-amino-acid research peptide corresponding to the mature human cathelicidin antimicrobial peptide. It is examined in controlled laboratory environments for its role in innate host-defense mechanisms, membrane interactions, immune signaling, inflammatory pathways, and cellular responses.

LL-37 is the only known human cathelicidin and is generated naturally through proteolytic processing of the hCAP-18 precursor. Its cationic and amphipathic characteristics have made it an extensively investigated peptide in antimicrobial and immunological research.

Product Description

Technical Specifications

• Product: LL-37
• Quantity: 5 mg
• PubChem CID: 16198951
• Molecular Formula: C₂₀₅H₃₄₀N₆₀O₅₃
• Molecular Weight: 4493 g/mol
• Peptide Length: 37 amino acids
• Sequence: LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES
• Purity: ≥99% (99.83% HPLC-UV tested for current lot)
• Form: White lyophilized powder
• Synthesis Method: Solid-phase peptide synthesis
• Synonyms: Cathelicidin LL-37, CAP18, Ropocamptide

The molecular formula, molecular weight, sequence, PubChem identifier, and synonyms are reported by PubChem’s LL-37 database entry.

CAS note: I would not put a CAS number on this page yet. The commonly encountered 597562-32-8 refers to an LL-37 amide/trifluoroacetate form in PubChem, rather than clearly identifying the unmodified LL-37 structure described above. I don’t want OPTMZ publishing a potentially incorrect identifier just to fill the field.

Analytical & Testing

Each batch of LL-37 undergoes high-performance liquid chromatography (HPLC) and mass spectrometry analysis to verify purity, identity, and analytical consistency. A corresponding Certificate of Analysis (COA) is available for each tested batch.

For the current OPTMZ Peptides lot, independent analytical testing reported:

• Identity (LC-MS): Confirmed as LL-37
• Purity (HPLC-UV): 99.83%
• Measured Net Content: 6.03 mg
• Appearance: White lyophilized powder
• Endotoxin Replicate 1: Pass
• Endotoxin Replicate 2: Pass
• Assay Sensitivity: ≤0.05 EU/mL

The COA identifies the sample as lot 2L5 and documents HPLC-UV/LC-MS analysis and endotoxin testing using the Limulus Amebocyte Lysate assay under validated laboratory conditions.

Handling & Storage

This compound should be handled by qualified professionals in controlled laboratory environments. Appropriate laboratory storage conditions should be maintained to preserve peptide stability and structural integrity.

Avoid unnecessary exposure to heat, moisture, and repeated temperature fluctuations. Laboratory handling procedures should be determined according to the requirements of the intended experimental protocol.

Research Context

In preclinical and laboratory research models, LL-37 has been investigated across microbiological, immunological, biochemical, and cellular systems. Research areas include:

• Host-defense peptide biology
• Microbial membrane interactions
• Innate immune signaling
• Leukocyte and immune-cell signaling
• Cytokine-associated pathways
• Epithelial cell biology
• Endotoxin interactions
• Cellular membrane models
• Tissue-repair and re-epithelialization pathways

LL-37’s positive charge and amphipathic structure contribute to its interactions with negatively charged microbial membrane components. Research has also examined functions extending beyond direct antimicrobial activity, including immune-cell signaling and epithelial responses.

These observations are limited to controlled experimental environments and support ongoing laboratory investigation.

Research Application Scope

LL-37 continues to be evaluated for its relevance in experimental biology, particularly within studies involving antimicrobial peptide mechanisms, innate immunity, membrane biology, host-defense signaling, inflammatory pathways, and peptide-structure/function relationships.

Its 37-amino-acid sequence and cationic, amphipathic characteristics make LL-37 particularly relevant to laboratory investigations examining peptide-membrane interactions and host-defense mechanisms.

Use Statement

For laboratory research use only. Intended strictly for in vitro research applications.

Disclaimer

All products currently listed on this site are for research purposes ONLY.